Gluten is a protein found in barley, wheat and rye, and it should be avoided by those with coeliac disease. The immune systems of coeliac sufferers mistakenly identify substances found inside gluten as a threat, and attacks them. This causes damage to the intestines, making proper digestion of nutrients difficult. If you don't have coeliac disease there is no need for you to cut gluten from your diet, however, if you're unsure and would like to be screened – speak to your GP.